Liquid stuffing-box for steam-turbines.



PATENTED I001. 25, 1904 L. H NASH. LIQUID STUPFING BOX FOR STEAMTURBINE-S.

APPLICATION FILED MAR. 11, 1904.

2 SHEETS-SHEET 1.

N0 MODEL.

INVENTOR afiZmK/Q I WITNESSES:

Mae/mm No. 773,297. PATBNTED" JOGT. 25, 1904. L. H. NASH.

LIQUID STUI'FING BOX PO-R. STEAM TURBINE-S.

ABPLIOATION FILED MAR. 11 1904. no xonnL. mums-mum 2.

Win12 sgs: I 1111115111771:

UNITED STATES Patented October 25, 1904.

LEWIS HALLOOK NASH, OF SOUTH NORVVALK, CONNECTICUT.

LIQUID STUF'FING-BOX FOR STEAM-TURBINES.

PECIFICATION forming part of Letters Patent NO. 773,297, dated October25, 1904.

Application filed March 11 1904. Serial No. 197,624. (No model.)

1'0 all whom, it may concern.-

Be it known that I, Lnwrs HALLOCK NASH, a citizen of the United States,and a resident of South Norwalk, in the county of Fairfield and State ofConnecticut, have invented a new and useful Improvement in LiquidStuffing-Boxes for Steam-Turbines, &c., of which the following isaspecification.

My invention is directed to a device for securing an air-tight jointupon a rotating shaft as it passes out of a chamber-as, for instance,the cylinder of a steam-turbine. It is therefore a form of stufling-box.For this purpose I make use of a rotating liquid, as mercury, underrapid rotation to form theseal in an effective and novel manner, as Iwill presently describe.

Among the advantages of my improved liquid stufiing-box may be mentionedthe following: There is absolutely no leakage possible by the joint. Thefriction of the stufiing-box' is so small as to be negligible. Thebearing is self-adjusting and can run out of line without serious injuryand without leakage, and, what is of great value in a steam-turbine,there can no oil pass into the engine from without nor steam or waterpass out, and a perfect vacuum can be maintained. The main bearings ofthe engine can therefore be placed outside of the steam-chamber, wherethey can be taken care of and inspected, and the alinement of thestufiing-box will adjust itself. Thus the trouble of oil entering thesteamchamber of the turbine will be entirely overcome, and the waterfrom the condenser will ontain no oil, but can be used directly in theboiler.

i I have shown in the drawings my invention as applied to the shaft of asteam-turbine; but it will be understood that I do not confine myinvention to such use, as many other forms of devices can make use of myimproved stufiing-bo'x, nor do I limit my invention to the exact formshown, since various changes may be made in its form and constructionwithout departing from thespirit and scope of my invention.

The special features of novelty which constitute my improvement will becarefully pointed out in the claims concluding this specification.

Referring to the drawings, Figure 1 is a longitudinal section through asteam-turbine, showing one method of arranging the stuflingbox and theshaft-bearings. Fig. 2 is a crosssection on the line 2 2 of Fig. 1 andalso shows a method of introducing the liquid jointforming material.Fig. 3 is an enlarged detail of the stuifing-box to illustrate theaction of centrifugal force in maintaining the joint. Fig. 4 is anenlarged view of the collar, showing means for producing an increasedrotation of the liquid. Fig. 5 is an enlarged view-of the shaft andcollar, showing the grooves and intervening projections. Fig. 6 is anend view of the same. Fig. 7 is a section of a modified formofstufiing-box in which the receptacle for holding the revolving fluidis carried by the shaft.

In Fig. l I have shown a section through the bearings and case of asteam-turbine at the shaft, the case and power-wheel being shown inbroken section, since my invention only relates to the parts shown inrelation to the shaft and its bearings. 3 is the shaft, which isprovided with collars 4. 4, preferably formed solid with the shaft. 5 isthe turbinewheel, which is inclosed between the casewalls 6 6, whichform the closure for the chamber 7. The shaft 3 passes through holes inthese case-walls 6 6, and aflanged cylinder 8 8 is secured to each sideof the case, so as to cover the collars 4 4 and form a circular chamber10, in which the collars can freely revolve. The shaft-bearings 9 9 areplaced outside of the case-chamber on each side of the same. Thechambers 10 10 are filled with mercury 11 11 or some other suitableliquid, which may be introduced through a pipe 12 from a reservoir 13,as shown in Figs. 1 and 2. This pipe 12 enters the chamber 10 through anorifice 14 at the point where it is desired to maintain the level of theliquid 11, and the liquid in the communicating vessel 13 is maintainedat the same level, so that in the operation of the device the liquidwill flow in or out of this reservoir to maintain this condition.

In Fig. 3 I have shown an enlarged view of the stufling-box in order toillustrate the action of the device.

Suppose the shaft 3 to be revolving at a high speed and that therevolving liquid assumes an annular position, as shown in section inFig. 3. Then if there were no difference in the pressures on theopposite sides of the collar at the level of the liquid on the two sideswould be the same; but if there were a vacuum on the side 7 and apressure on the opposite side this difference in pressure would forcethe liquid outward on the side where the pressure is greatest and inwardwhere the pressure is least and would produce a difference of level 71on the two sides of the collar, as illustrated in the drawing. Theaction of the centrifugal force will resist this tendency, and thedistance or head it will represent the ference in pressure on theopposite sides of the collar 4:.

When the speed of rotation of the shaft is very high, as insteam-turbines, a smooth collar 4 will have enough friction to cause theliquid to rotate with sufficient velocity to produce the necessarycentrifugal force; but with slower-running shafting it may be desirableto have the liquid rotate as fast as the shaft, and in this case 1 formgrooves or paddles on the collar to increase the rotation of the fluid.In Figs. 4, 5, and 6 I have shown one way to accomplish this result, andthis is done by forming surface grooves 15 15 in each side of the collar4, which will increase the friction of the collar in the liquid, as willbe readily understood; but I do not confine my invention to anyparticular'construction of grooves or paddles, as many variations inform are possible to secure the desired result.

In Figs. & and 5 the grooves are used to ,form an irregular surfaceonthe collar, and the intervening projecting surfaces act as paddles toimpel the liquid and cause it to rotate rapidly in the groove or recessof the case.

The operation of the device is as follows: Suppose the shaft to berunning at a speed of thirty thousand revolutions per minute, or fivehundred revolutions per second, and that the mercury rotates at one-halfthe speed of the shaft, or at the rate of two hundred and fiftyrevolutions per second, then by the formula for centrifugal force F o'wnx 1.2276, in which 20 is the weight of the body, 7 is the radius infeet, and n is the revolutions per second. If wis one inch,f equals6,250 w. that is to say, with a flange or collar dipping into themercuryat a distance of one inch from the center of the shaft thecentrifugal force would be six thousand two hundred and fifty times asgreat as the force of gravity, and a vacuum of thirty inches of mercurywould produce a difference of level [L of thirty six-thousandtwo-hundredand j fiftieths, or one two hundred-and-eighths of an inch. The resultof this surprising fact will be understood on reflection. The liquidunder the action of this strong centrifugal force becomes almost rigidagainst distortion of its shape, and it will resist any such action asif it was an elastic solid. VVhilc it is still a liquid and will morelike one, it will hold its place against any lesser force than thatwhich acts to keep it in place, and under the conditions assumed avacuum would hardly move it at all and a perfect contact will bemaintainedbetween the shaft and the case-chamber. If the collar shoulddip one-eighth of an inch into the mercury, the pressure on the face ofthe collar would equal seven hundred and eighty inches of mercury; butas this is balanced on all sides of the shaft it runs in a cushion ofmercury.

It will be understood that I may use other liquids besides mercury asthe joint-forming fluid; but for steam-turbines I prefer to use mercury,because if the case-recess should fill up on one side with oil or on theother side with water the gravity of the mercury will still hold thejoint and the oil or water will simply float upon the surface of themercury, but it will not be able to pass the collar.

In the case of slower-running shaft-ing it may be desirable to increasethe rotation of the liquid to that of the shaft in order to secure thegreatest centrifugal force. For this purpose I form the collar withgrooves or projections, so as to drive the liquid around in the recessat the highest possible speed. This feature is illustrated in Fig. 4 andhas already been described. It will be seen that th collar is in realitya diaphragm which is joined at one side to the shaft and 'on the otherside it makes joint with the revolving liquid, and in this way it formsa complete separation between the two sides.

In Figs. 1 and 3 of the drawings 1 ha shown the mercury as carried in achamb J.)- in the case; but it is obvious that the shaft may carry a cupcontaining the mercury and that the diaphragm may be secured to thecase.

In the modification shown in Fig. 7 a circular flange 16 is secured tothe shaft so as to form an air-tight fit upon it. This flange has acylindrical extension, to which a flange 18 is secured, so as to form anannular recess to contain the rotating liquid. An extending cylinder 17is secured to the case 6 and at its inner end it carries a collar 19,which dips into the liquid 11. It will thus be seen that the recesswhich carries the joint-forming liquid revolves with the shaft and thattherefore the said liquid will rotate at about the speed of the shaft.The joint-forming action of the liquid is,h0wever, not different fromthat shown in the figures before described.

I claim- 1. A stufling-box comprising an annular chamber containing aliquid and a disk. the periphery of which extends into said chamber, oneof said parts being adapted to be ma1nions in Correct tained in rapidrevolution, whereby the liquid is caused to rotate in said chamber toform a joint between the disk and the chamber.

2. A stufling-box comprising an annular chamber containing a liquid anda disk, the periphery of which extends into said chamber, one of saidparts being provided with projections and adapted to he maintained inrapid revolution, whereby the liquid is caused to rotate in said chamberto form a joint between the disk and the chamber.

3. A stuffing-box comprising an annular chamber containing a liquid anda disk, the periphery of which extends into said chamber, one of saidparts being adapted to be maintained in rapid revolution, whereby theliquid is caused to rotate in said chamber to form a joint between thedisk and the chamber, and a reservoir of liquid connected with saidchamber.

4:. The combination of a shaft having a projecting collar, with aclosure surrounding said collar and means for causing a liquid to rotatein said closure and form a seal by its centrifugal force, between theshaft and the closurewalls, for the purpose specified.

5. A stuffing-box, comprising a fixed part and a part combined with arotating fluid rotated by said rotating part intervening and forming ajoint between said parts.

6. The combination ina liquid stufling-box, of a shaft having a collarwith a closure surrounding said collar and a pipe having an opening insaid closure at the level of the surface of the liquid in said closure,and means for supplying the pipe with liquid for the purpose specified.

7. A shaft-packing comprisinga casing provided with an annular chamberfor receiving a liquid surrounding said shaft, a collar secured to saidshaft and extending within said chamber whereby the liquid is caused torotate in said chamber.

8. The combination in a liquid stuffing-box of a shaft having a collarand a case having an annular recess adapted to retain a liquid underrotation surrounding said collar, with means for causing the liquid torotate.

9. In a liquid stufiing-box, the combination of the shaft and itscollar, with a case-recess inclosing said collar adapted to contain aliquid under high rotation, and projections on said collar for causingsaid liquid to rotate.

10. A stufling-box comprising a fixed part and a part combined with arotating body of mercury rotated by said rotating part intervening andforming a joint between said parts.

In testimony that I claim the foregoing as my invention I have signed myname, in presence of two Witnesses, this 9th day of March, 1904:.

CHAS. A. HAVILAND, E. W. HAVILAND.

t is hereby certified that in Letters Patent No. 773,297, grantedOctober 25, 1904,

upon the application of Lewis Hallock Nash, of 'South Norwalk,Connecticut, for an improvement in Liquid Stufling-Boxes forSteam-Turbines, errors appear in the printed specification requiringcorrection, as follows: In line 28, page 3, the word rotating before theword fluid should be stricken out and inserted before the word part,"same line, and in line 55, same page, the word rotating before the wordbody should be stricken out and inserted before the word part, same lineand same page and that the said Letters Patent should be read with thesecorrections therein that the same may conform to the record of the casein the Patent Ofliee.

Signed and sealed this 6th day of December, A. D., 1904.

[snark] F. I. ALLEN,

Conum'ssioner of Patents.

ions in Correct tained in rapid revolution, whereby the liquid is causedto rotate in said chamber to form a joint between the disk and thechamber.

2. A stufling-box comprising an annular chamber containing a liquid anda disk, the periphery of which extends into said chamber, one of saidparts being provided with projections and adapted to he maintained inrapid revolution, whereby the liquid is caused to rotate in said chamberto form a joint between the disk and the chamber.

3. A stuffing-box comprising an annular chamber containing a liquid anda disk, the periphery of which extends into said chamber, one of saidparts being adapted to be maintained in rapid revolution, whereby theliquid is caused to rotate in said chamber to form a joint between thedisk and the chamber, and a reservoir of liquid connected with saidchamber.

4:. The combination of a shaft having a projecting collar, with aclosure surrounding said collar and means for causing a liquid to rotatein said closure and form a seal by its centrifugal force, between theshaft and the closurewalls, for the purpose specified.

5. A stuffing-box, comprising a fixed part and a part combined with arotating fluid rotated by said rotating part intervening and forming ajoint between said parts.

6. The combination ina liquid stufling-box, of a shaft having a collarwith a closure surrounding said collar and a pipe having an opening insaid closure at the level of the surface of the liquid in said closure,and means for supplying the pipe with liquid for the purpose specified.

7. A shaft-packing comprisinga casing provided with an annular chamberfor receiving a liquid surrounding said shaft, a collar secured to saidshaft and extending within said chamber whereby the liquid is caused torotate in said chamber.

8. The combination in a liquid stuffing-box of a shaft having a collarand a case having an annular recess adapted to retain a liquid underrotation surrounding said collar, with means for causing the liquid torotate.

9. In a liquid stufiing-box, the combination of the shaft and itscollar, with a case-recess inclosing said collar adapted to contain aliquid under high rotation, and projections on said collar for causingsaid liquid to rotate.

10. A stufling-box comprising a fixed part and a part combined with arotating body of mercury rotated by said rotating part intervening andforming a joint between said parts.

In testimony that I claim the foregoing as my invention I have signed myname, in presence of two Witnesses, this 9th day of March, 1904:.

CHAS. A. HAVILAND, E. W. HAVILAND.

t is hereby certified that in Letters Patent No. 773,297, grantedOctober 25, 1904,

upon the application of Lewis Hallock Nash, of 'South Norwalk,Connecticut, for an improvement in Liquid Stufling-Boxes forSteam-Turbines, errors appear in the printed specification requiringcorrection, as follows: In line 28, page 3, the word rotating before theword fluid should be stricken out and inserted before the word part,"same line, and in line 55, same page, the word rotating before the wordbody should be stricken out and inserted before the word part, same lineand same page and that the said Letters Patent should be read with thesecorrections therein that the same may conform to the record of the casein the Patent Ofliee.

Signed and sealed this 6th day of December, A. D., 1904.

[snark] F. I. ALLEN,

Conum'ssioner of Patents.

Letters I;

ions in Correct It is hereby certified that in Letters Patent No.773,297, granted October 25, 1904, I upon the application of LewisHallock Nash, of'Sohth Norwalk, Connecticut, for an i improvement inLiquid Stuffing-Boxes for Steam-Turbines, errors appear in the printedspecification requiring correction, as follows: In line 28, page 3, theWord rota-ting before the word fluid should be stricken out and insertedbefore the word part," seine line, and inline 55, same page, the wordrotating before the word hody should be stricken out and inserted beforethe word part, same line and same page; and that the said Letters Patentshould be read with these corrections therein that the same may conformto the record of the case in the Patent ()fiice.

Signed and sealed this 6th day of December, A. D., 1904.

[snub] F. I. ALLEN,

Connnissioner of Patents.

